This invention generally relates to the manufacture of glass components for television picture tubes. More particularly, this invention relates to the manufacture of the glass funnel portion of a television picture tube by a centrifugal casting process. Yet more particularly, this invention relates to a transfer mechanism for mold rings for this centrifugal casting process. Specifically, this invention relates to an improved operating mechanism for the transfer mechanism in such a process.
The manufacture of glass parts for television picture tubes, in particular funnels, by a centrifugal casting process is well known in the art. See, for example, U.S. Pat. Nos. 3,132,018 and 3,589,882. One requirement of such a process is the transfer and orientation of a mold ring for the main mold. Devices to carry out this aspect of the process are also known in the art. See, for example, U.S. Pat. Nos. 3,597,181 and 3,708,274. The mechanism shown in U.S. Pat. No. 3,597,181 has been particularly successful in commercial operations. However, its arm opening mechanism and carrying arms themselves have been subject to relatively high maintenance requirements. We have devised an improved mechanism for that machine which incorporates substantially improved carrying arms and actuation mechanisms for them.